The Siam is in the historic Dusit neighbourhood, home to royal palaces and government buildings, set on the Bangkok side of the Chao Phraya River at the base of the Krung Thon Bridge.
Fly into Bangkok's Suvarnabhumi Airport (www.bangkokairportonline.com), 35 kilometres east of the city centre, which handles domestic and international flights. Take the Bangkok Airport Train (www.bangkokairporttrain.com) from Suvarnabhumi for fast, traffic-dodging links into town; the last stop, Phaya Thai, is the nearest to the Siam.
The nearest regular train station is Hua Lamphong (www.railway.co.th), five kilometres from the Siam, Bangkok's major train hub serving destinations including Chiang Mai, Chiang Rai and former royal capital Ayutthaya.
If you've arrived with your own wheels, there's free parking at the hotel. Taxis and tuk-tuks for local journeys are available around the clock, but beware of peak traffic times.
The Siam has its own dedicated river pier and offers a private speedboat shuttle to and from Bangkok's Sathorn Central Pier, 25 minutes to the south, just a hop from the BTS Skytrain stop at Saphan Taksin.
Worth getting out of bed for
The Siam's intimate Opium Spa by Sodashi is a must for pleasure hounds, drawing on all-natural products inspired by the earth and sea. Choose between solo or couple's suites with steam rooms and saunas. Facials, body therapies, massage, mani/pedis and wellbeing programmes are all up for grabs. The Kids' and Teen Menu is a cute touch, and there are specific pampering perks for men.
It's not often that hotel gyms tick the good-looking box, but the Siam's is spacious and serene, overlooking a monastery, with personal trainers on tap. Unwind on the outdoor yoga terrace, with a cocktail at sunset, try t'ai chi or get fighting fit in the muay Thai ring (the spa offers a Muay Thai Recovery package if you overdo it). Training options abound for beginners or experienced boxers, and the chef can even tailor your diet to match.
For cultural highs, ogle hand-picked curios and antiques in the hotel's cabinets and inviting library (home to owner Krissada Clapp's collection of rare, first-edition hardbacks on old Siam and Asia and his mother Kamala's neolithic pottery pieces).
You're just 15 minutes from the Grand Palace, and mesmerising temples Wat Pho and Wat Arun downstream. Make the most of the Siam's free shuttle for gliding to riverside sites, or let the concierge hook you up with an in-the-know private guide. Smith also recommends checking out the floating markets and sleepy scenes on the city's smaller khlongs (canals), easily expored by longtail boat. The hotel also has a private Bangkok boat tour. Fans of muay Thai can watch the real thing at nearby Ratchadamnoen Stadium.
Further afield to the north, the Chatuchak Weekend Market is worth a visit, with hundreds of stalls toting clothing, handicrafts, homewares, food and pets (live snakes, anyone?). The shopping-averse can content themselves with Curio, the Siam's small boutique, which offers an elegant edit of accessories, from travel posters to jewellery, antiques and toiletries.
For a fantastic local experience near the hotel in Thewit, head for Krua Apsorn (503–505 Samsen Road), a cosy dining room which has served members of the Thai royal family and bagged press plaudits. Crab, shrimp, snapper and mussels star in a range of tasty curries and stir-fries for lunch or early supper, backed up by soups, papaya salad and coconut ice-cream. Another good bet nearby is Rosabieng Restaurant (3 Sukhumvit soi 11), which serves delicious Thai food and cool beers on the terrace.
Phra Athit Road, just south of Dusit near the Chao Phraya River, is a charming spot with a host of hip cafés, bars and restaurants set in beautiful old shophouses.
Stick with the Siam's musical theme by popping out for a drink at neighbourhood jazz bar Brown Sugar, at 469 Phrasumen Road. It's open in the day for coffee or lunch, with drinks and live music nightly until the wee hours. In for a quiet night? Come evening, make time for a movie in the atmospheric screening room off the hotel lobby, equipped with classic folding wood-and-velvet French cinema seats. The space also screens Thai history clips and hosts guest speakers.